var maxSlidingWindow = function(nums, k) {
    const len = nums.length
    const res = []
    const deque = []
    for(let i = 0;i < len;i++) {
        while (deque.length && nums[deque[deque.length - 1]] < nums[i]) {
            deque.pop()
        }
        deque.push(i)

        //当队列头部存放的值 和 i形成的区间大于窗口宽度时
        while (deque.length && deque[0] <= i-k) {
            deque.shift()
        }

        //该取最大值
        if (i >= k-1) {
            res.push(nums[deque[0]])
        }
    }
};